Using CMOM for Stormwater

Using CMOM for Stormwater

When most people think about the EPA’s capacity, management, operations, and maintenance (CMOM) program, they think about its application to wastewater. The goals of this method include proactively avoiding sanitary sewer overflows, establishing best practices for responding to overflows when they happen, and ensuring communities are able to operate their collection systems effectively. However, CMOM can also be highly useful for municipal stormwater programs and is an option worth considering for those working on addressing asset renewal and compliance needs in their stormwater systems.

Applying CMOM to stormwater in New England

Portland, Maine is one of the oldest cities in the country, and the largest in the state. Like most other cities in the Northeast, the set of Clean Water Act requirements it must adhere to are complex, and the city recently invested in the creation of a Sanitary Sewer System CMOM Assessment and Corrective Action Plan. That plan assessed the strengths and weaknesses of its systems and identified critical and influential needed improvements.

With a plan completed, that focused on eliminating sanitary sewer overflows and effectively managing that utility, the city recognized the benefit they’d gain from developing a similar plan for its storm sewer system. Portland decided to use the CMOM tools to apply the same principles to its storm sewers, drainage system assets, and programs. With an ultimate city goal of developing an integrated Clean Water Act compliance program, this stormwater system plan was the next step in beginning to prioritize compliance requirements and managing its stormwater drainage assets in the same way it had previously done for its sanitary systems. The result of this effort will be a Stormwater System Master Plan that incorporates the fundamentals of Asset Management within a CMOM Assessment. This will allow the city and its partners to create defendable cost estimates for annual budgeting and prioritize the allocations of funds.

Asset management in the CMOM framework

For utilities and municipalities, asset management makes it possible to maintain the desired level of customer service while controlling the life-cycle cost of owning and operating their infrastructure. When applied correctly it can prolong the life of assets and provide a framework for making organizational choices that improve the efficiency of operations and enable utilities and municipalities to maintain regulatory compliance through focused efforts. In Portland’s case, the most important piece of its asset management strategy was using principles of criticality.

An asset’s criticality can be described as the relative cost of the consequences that result from its failure. This could include the costs of replacement, revenue lost during downtime, or third-party harm that drives legal or liability expenses. When evaluating criticality, it’s also important to consider the potential impacts of any component’s failure on human health and the environment; from this perspective, keeping an outfall or its contributing drainage system in good repair is a priority for capital investment if the outcome of failure would be discharging pollutants to a popular public use area. Assigning levels of criticality leads directly to a better understanding of individual system components, more specific goal creation and key performance indicators, and the capacity to implement practices that prevent service interruption; this in turn provides a basis for comprehensive and reliable operations and maintenance.

The CMOM framework presents a useful lens for examining both your wastewater and stormwater drainage system assets. If your utility has already applied the principles of CMOM to sanitary or combined sewer systems, it might be time to begin the process of creating a plan for your storm sewer system’s capital and operational investments, using asset management as a guide.


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